Safety device for elevators



(No Model.)

y C. C. PALMER.

SAFETY DEVICE FOR ELEVATORS. 110,261,101. A Patented Ju1y11,1882.

N. FUER; Phoxvumosmvmr, wa-hingmn. D. CA

UNITED STATES .l PATENT Ormea.

cAssiUs c. PALMER., on OAKLAND, cALinoRNIA.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 261,101, dated July 11,1882. Application filed August l0, 1881.` (No model.)

To all whom it may concern Be it known that I, CAssiUs C. PALMER, ofOakland, in the county of Alameda and State of Galifornia,have made andinvented certain new and usefniImprovements in Safety Stop Devices-for'Elevatorsg and I do hereby declare that the following is afull,clear, and exact description of the same, reference lbeingy ofaction by the hoisting-rope or by catches of some kind controlleddirectly or indirectly by the hoisting-rope, and which can act torelease the springs and throw the clutches against the guides or runs ofthe elevator only when the tension or pull of the rope is taken off thecatches, while iii/another kind the gripping devices are acted upon byamechanical device fixed on the elevator, that remains inactive so longas the regular speed of the elevator is maintained; but is thrown intoaction and caused to trip or otherwise operate the gripping device orclutches whenever the downward movement of the elevator is quickenedbeyond its usual rate of speed. Such devices, however, I have found tobe defective in principle and uncertain in action. The increased speedor downward movement that is required of the elevator to bring thelast-named device into action and operate the clutches producessufficient momentum in a heavily-loaded cage to breakV the clutches whenthey are thrown out against the sides of the elevator well or shaft,while in the rst-named construction the safety-clutches will be held outor will not act properly unless the hoisting-rope breaks in the vicinityof the cross head or upon that side of porting and carrying the dogs orclutch device Y from and by an independent cross-head or frame, and arope running at uniform speed with the hoisting-rope, but detached anddisconnected therefrom, by which the clutches are carried along with theelevator in its up and down movements by the independent rope, and arecaused to be operated or thrown into action by the sudden drop ordownward move-l ment of the elevator Without the aid of springs,mechanical devices of any kind, or the services of an attendant.

In the vaccompanying drawings herein referrcd to, Figure 1 shows myinvention as applied to a freight or platform elevator of the or. dinaryconstruction. Fig. 2 is a plan View ot' the safety device. Fig. 3 showsthe application of my device to a cage or passenger-elevator of theheavier kind. Fig. 4 is a plan view of the safety device in Fig. 3.

To carry out my invention I provide a sheave or pulley upon t-he sameshaft with the pulley of the principal hoisting-rope, and over thispulley I carry a rope, A, independently of, but s0 as to travel at thesame speed with, the hoisting-rope. This rope A, I employ to support andcarry alight cross-head,B,which is moved up and down uniformly at thesame speed as the elevator cage or platform. Beneath the elevator flooror platform I arrange a set or sets of friction dogs or clutches ofsuitable construction to engage with, bite, or grip the guides, runs, ortimbers on the sides of the elevator shaft or well, and I suspend andsupport these clutches from and by the cross-head B above by means ofrods or ropes b b. These clutches are so applied that the weight orpressure of the cage or platform is caused to act directly upon them andthrow them out against the sides of the elevator-shaftwhenever thedownward movement of the elevator exceeds the movement of the travelingcross-head B.

A simple and eicient modeof constructing and applying the clutches to beacted upon by the downward drop of the elevator is shown IOO in Figs. land 2 of the drawings, where I x in a strong and substantial frame, C, aset of pivoted clutches, d d, at each side to engage with the runs orguides fw w of the elevator and support and carry this frame by thecrosshead B and the rods b b, so that it shall move easily up and downat uniform speed with the elevator. I have this frame C to move alwaysat a distance below the tloor or platform of the elevator, so that whilethey both travel together there shall be a space between the under sideof the elevator and the top surface of the frame U, and this space mustbe sufficient to keep the bottom ofthe cage or platform out 0f contactwith the clutching mechanism, or the weight of the elevator` oft` thearms or levers that throw out the clutches while the elevator is workingproperly. At each side of this frame C, I tix the clutches d d, so thatthey shall act, when thrown out to bite or grip the ways w, either onthe face of the way, as shown in Fig. 1, or against both the face andsides, as shown in-Fig. 4t; and I construct thc clutch with a grippingportion, d, serrated or roughened, it' required, to run next to thesurface of the way w, and a lever arm or bar,f, the end g of whichprojects and is held up above the top surface of the frame C, either bythe weight of the heavier portion d or by the aid of a spring, e. Now,by this construction the clutches d d will be supported and kept out ofaction beneath the cage or platform by the cross-head and rope A as longas the elevator and the crosshead run together up and down at theregular speed; but when the weight of the elevator is thrown down orbrought to bear on the clutches they will be thrown out mechanically andinstantaneously, and will act to stop the elevator and hold it at anypoint. Thus the clutches are operated by the drop or pressure of theelevator without the aid of springs and without depending on the serviceor attention of an operator to work them.

In elevators of the heavier kind the clutchcarrying frame can be madecorrespondingly stronger, and additional clutches g g can be used, as inFigs. 3 and 4. of the drawings, to engage with p0sts,guides, or timberww,pro vided at each side of the principal guides fw. In this case thecross-head or frame B b b, that travels with the elevator,can besupported and carried by two independent ropes, A A.

It will be evident to any one familiar with the construction and use ofelevators that the weight of the cross-head B and connected parts mustbe counterpoised by using weights at the other end of the rope A, or byrunningy the rope over a windingdrum after the manner of working thehoisting-rope, so that the ropes shall travel at uniform speed, and theweight of the clutching device shall be properly supported beneath theelevator iioor or platform. This construction and arrangement,

however, can be changed and varied as may be required or considerednecessary without departing from the nature and principle of myinvention, as the essential feature thereofconsists in the use of theindependent traveling rope and cross-head supporting a clutch devicebeneath the floor or platform of an elevator in position to bc actedupon by the drop of the elevator.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is

l. In an elevator or hoisting works, the independent traveling rope andcrosshead, in combination with a clutch device beneath the hoor orplatform of an elevator, said clutch device being adapted to be throwninto action by the drop or pressure of the elevator when falling, but tobe held out of action or inoperative as longas the rope, cross-head, andelevator travel uniformly together, substantially as herein described.

2. The safety-frame C, having clutches for engaging with the guides tuof an elevator shaft, in combination with said guides, and with a rope,A, whereby the frame is suspended and moved independently ot' butnniformly with and beneath the cage or platform of anelevator,substantially as herein described.

3. The combination, with the cage or platform of an elevator, of asafety clutch device supported and carried beneath the elevator Hoor orplatform from and by an independent traveling rope, and adapted to moveup andl down uniformly with the elevator, substantially as described.

4. Aframe,G, suspended beneath and caused to travel at uniform speedwith an elevator cage or platform, and having a clutch 0r stop mechanismconsisting of the pivoted levers f. and heads g', projecting above theupper surface ofthe frame C, which is adapted to be operated by the dropor fall of the elevator down upon the said frame, substantially asherein described.

5..'Ihe combination, with the cage or platform of an elevator, of anindependently-supported traveling frame moved and traveling uniformlywith and beneath the elevator, and having a clutch device at each side,the operating mechanism ofwhich projects above the surface of said frameand so as to be struck or acted upon by the weight or pressure of theelevator when it drops, substantially as'here in described, for thepurpose set forth.

h In witness whereof I have hereunto set my and.

CASSIUS CLAY PALMER.

Attest: f

W. F. CLARK, EDWARD E. OsBoRN.

IOO

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